Will a pendulum clock lose or gain time when taken to the top of a mountain?

Will a pendulum clock gain or lose time when take to the top of a mountain?

Will pendulum clock lose or gain time on hills or inside the mines ?

A pendulum clock, which keeps correct time at sea level, loses 15s per day when taken to the top of a mountain. If the radius of the earth is 6400km , the height of the mountain is

A pendulum clock, which keeps correct time at sea level, loses 15s per day when taken to the top of a mountain. If the radius of the earth is 6400km , the height of the mountain is

When a pendulum clock gains time, what adjustiment should be made?

when a pendulum clock gains time , what adjustments should be made ?

A pendulum clock keeping correct time is taken to high altitudes